The Statistical and Data Management Core will provide statistical and data management support to the Seattle TREC Center projects and cores. The biostatistical staff will provide expertise in experimental design, sample size requirements, and statistical analysis. They will also assist project investigators in the summarization of data and the preparation of manuscripts for publication. The data operations staff will implement and maintain the Specimen Tracking System, control and track the data flow from and to all projects and cores of the Seattle TREC Center through the Data Flow Tracking Module, take the lead in tracking some project recruitment and intervention efforts through the Study Participant Tracking Module, track the progress on, and support the assembly of, high quality data from varying sources into analysisready datasets, and deliver the data in SAS or SPSS datasets for analysis by the Core's biostatisticians or the investigators of the projects. The data operations staff will also jiaise with the TREC coordinating center, will provide datasets for combined analyses across TREC centers, and will collaborate with other TREC centers for developing compatible data systems where appropriate. This core uses personnel from two programs within the FHCRC, namely the Biostatistics Program and the Cancer Prevention Program. All staff have offices in the Public Health Sciences building on the FHCRC campus. Regular shuttle service is available between the campus and the University of Washington. All staff have access to networked computing support and standard statistical packages, such as SAS, SPSS, SPlus, STATA, and Microsoft Access. The data operations staff has a total of 5 Pentium stations, linked into the Cancer Prevention Program file servers, and backed up and otherwise maintained by the Cancer Prevention Program network administrators. All staff are also connected to the FHCRC wide-area network, which makes the transfer of data and programs between groups an uncomplicated task. The biostatistical and data operations staff also has experience with using collaborative web-based datasets in other studies. We will use this capability in the proposed TREC Center, particularly in data transfer from study labs and between study investigators.